Negative-positive pressurizable implant

ABSTRACT

A pressurizable implant, comprising a body and at least one porous arm extending from and interconnected to the body, the at least one porous arm being configured to accommodate a pressure gradient that is created by a device removably connectable to the body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related and claims priority to U.S. ProvisionalPatent Application Ser. No. 61,533,374 filed on Sep. 12, 2011, thecomplete and entire disclosure of which is hereby expressly incorporatedby reference herein.

TECHNICAL FIELD

The present invention generally relates to a pressurizable implant, atleast a portion of which may be composed of a porous or mesh-likematerial, and more specifically to an implant adapted to create apressure differential that is configured to encourage tissue ingrowthand/or to allow materials such as medicines, antibiotics, growth factorsand blood platelets to be introduced at or around the implantation site.

BACKGROUND OF THE INVENTION

To promote and encourage the ingrowth of surrounding bony and softtissues, biomedical implants sometimes contain one or more poroussurface. In essence, these surfaces function as scaffolds, which providedesirable load-bearing strength at the implantation site as a result ofthe ingrown tissue.

While many implants have surfaces conducive to bony ingrowth, the depthof ingrowth penetration associated with these devices is not onlylimited by various biological factors, but is also limited by the factthat the ingrowth must be achieved without mechanical assistance.Moreover, in addition to promoting bony and soft tissue ingrowth, porousimplants may also undesirably introduce microbes and metabolic agentsinto the implantation site, thereby increasing the potential for aninfection to develop. Not only is the risk of infection increased, butthe presence of toxins, wound drainage fluid and other substances withinthe implantation site may further hinder the positive effects of theingrowth if they become trapped inside the porous material.

To minimize the increased threat of infection, biological pressuregradients are sometimes utilized during the surgical process. Thesepressure gradients not only enhance post-surgical recovery and healing(e.g., by assisting with wound closure and the application of suctionforces for draining bodily fluids and exudates), but they also directlycounter the onset of infectious conditions. Finally, they may also beused to irrigate wound sites by infusing them with pharmacologicalagents, such as medicines, antibiotics, growth factors and bloodplatelets.

The present invention is intended to improve upon and resolve some ofthese known deficiencies of the art.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, a pressurizableimplant is provided and comprises a body and at least one porous armextending from and interconnected to the body. The at least one porousarm is configured to accommodate a pressure gradient that is created bya device removably connectable to the body.

In accordance with another aspect of the present invention, a system forpressurizing an implant is provided. According to this aspect of theinvention, the system comprises a body having an internal chamber, atleast one porous arm extending from and interconnected to the internalchamber via a channel or duct, an airtight seal, and a device configuredto removably couple to the airtight seal to distribute a pressuregradient across the at least one porous arm.

In accordance with still another aspect of the present invention, amethod of distributing a pressure gradient across an implant during asurgical procedure is provided. According to this embodiment, the methodcomprises the steps of providing an implant having a body, an internalchamber and at least one porous arm extending from and interconnected tothe internal chamber via a channel or duct; placing an airtight seal inthe internal chamber; connecting a device to the airtight seal; andactuating the device to create a pressure differential across at least aportion of the implant.

Other objects and benefits of the invention will become apparent fromthe following written description along with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned aspects of the present invention and the manner ofobtaining them will become more apparent and the invention itself willbe better understood by reference to the following description of theembodiments of the invention taken in conjunction with the accompanyingdrawings, wherein:

FIG. 1 is a perspective view of a pressurizable implant in accordancewith the teachings of the present invention;

FIG. 2 is a front, cross-sectional view of the pressurizable implanttaken along line 2-2 of FIG. 1;

FIG. 3 is a front, cross-sectional view of another pressurizable implantin accordance with the teachings of the present invention;

FIG. 4 is a cross-sectional view of an implanted pressurizable implantin accordance with the teaching of the present invention, the implantaccommodating a pressure gradient as a user actuates a syringe connectedto the implant;

FIG. 5 is a front, cross-sectional view of a pressurizable implant inaccordance with the present invention and having a humeral headcomponent that is to be fitted into the implant during implantation;

FIG. 6 is a front, cross-sectional view of the pressurizable implant ofFIG. 5 after the humeral head component has been fitted into theimplant; and

FIG. 7 is a cross-sectional view of a patient's shoulder having apressurizable implant in accordance with the teachings of the presentinvention implanted therein together with a humeral head component.

DETAILED DESCRIPTION

The embodiments of the present invention described below are notintended to be exhaustive or to limit the invention to the precise formsdisclosed in the following detailed description. Rather, the embodimentsare chosen and described so that others skilled in the art mayappreciate and understand the principles and practices of the presentinvention.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although any method andmaterials similar or equivalent to those described herein can be used inthe practice or testing of the present invention, the specific methodsand materials are now described. Moreover, the techniques employed orcontemplated herein are standard methodologies well known to one ofordinary skill in the art and the materials, methods and examples areillustrative only and not intended to be limiting. Furthermore, whilethe present teachings for the disclosed pressurizable implant aresometimes described in association with a humeral head component andshoulder prosthesis, those skilled in the art will appreciate that thepresent teachings may be incorporated into various other orthopedicimplants for a human body such as knee, hip, and other joints.Therefore, it is to be understood that the present illustrativeembodiments are not meant to limit the present invention.

The following detailed description, beginning with FIG. 1, illustrates apressurizable implant device constructed in accordance with the presentteachings and generally identified by reference numeral 10. Thepressurizable implant 10 is generally defined by a housing or body 12that has an inner surface 14 and an outer surface 16. A plurality ofarms or fins 18 are arranged around the outer surface 16 of the body 12,and, in accordance with certain embodiments, are formed entirely of aporous material that extends from the inner surface 14 of the body 12 tothe outer surface 16. In certain specific embodiments, the porousmaterial is comprised of a metal selected from one or more of stainlesssteel, titanium, titanium alloys, cobalt-chromium alloys and othermaterials that are suited for use in a biocompatible environment. Whileit should be understood and appreciated herein that the body 12 of theimplant 10 may also be formed of a porous material, in accordance withcertain aspects of the present invention, the body 12 is at leastpartially formed of a non-porous material, such as stainless steel,titanium, titanium alloys, cobalt-chromium alloys and other materialsthat are suited for use in a biocompatible environment. It should alsobe understood and appreciated herein that the size and shape of theimplant can depend on the specific implantation procedure beingconducted on the patient. In certain embodiments, however, the body 12is cylindrical and has an opening at its top to accommodate an internalchamber 20.

Referring now to FIG. 2, a front, cross-sectional view of thepressurizable implant 10 taken along line 2-2 of FIG. 1 is shown. As canbe appreciated from this illustration, the arms or fins 18 areinterconnected to the internal chamber 20 of the body 12 by way of oneor more channels or ducts 22. It should be understood herein that thoseof skill in the art can vary the specific size, number and orientationof the associated channels or ducts 22, particularly as these propertieswill largely be dependent upon the specific implantation procedure beingperformed. However, as will be discussed below, in accordance withcertain aspects of the present invention, the channels or ducts 22 aresized so that they accommodate and facilitate the ingrowth ofsurrounding bony and soft tissues by allowing a pressure gradient to becreated and distributed across the implant. In accordance with certainspecific aspects of the present invention, the average pore size of thedisclosed porous material may be from about 100 microns to about 700microns, and the average porosity may be from about 40% to about 80%.

FIG. 3 shows a front, cross-sectional view of another pressurizableimplant 10 in accordance with the present invention. In accordance withthis alternative aspect of the present invention, the plurality of armsor fins 18 are formed of a porous material, as well as include a seriesof branched channels 24 that extend from the inner surface 14 of thebody 12 to the outer surface 16. In certain specific embodiments, theporous material is comprised of a metal selected from one or more ofstainless steel, titanium, titanium alloys, cobalt-chromium alloys andother materials that are suited for use in a biocompatible environment.While it should be understood and appreciated herein that the arms orfins 18 of the implant 10 may be formed of a porous material, inaccordance with certain aspects of the present invention, the arms orfins 18 may also be formed of a non-porous or partially porous material,wherein the branched channels 24 are etched or formed within the arms orfins 18 as desired. Those of skill in the art should understand andappreciate herein that one of the specific benefits of the branchedchannel configuration shown in FIG. 3 is that the channels 24 can bespecifically designed to mimic the natural vascular shape and structurefound within the human body. In addition, because the branched channels24 can be designed to mimic specific orientations, it is possible toisolate where pharmacological agents are delivered into the bodyrelative to these channels. To design the channels 24 in accordance withthe teachings of the present invention, those of skill in the art willunderstand that known techniques such as additive manufacturingprocesses can be used.

With reference to FIG. 4, the arms or fins 18 of the present inventionare configured to create and distribute a pressure differential orgradient by way of a device that is capable of altering the associatedpressurization properties of the implant 10. Here, the implant device 10is placed inside a humerus 40 as part of a shoulder procedure, and asyringe 30 is connected to the implant 10 device by way of a tube 32. Tocreate and distribute a negative pressure gradient across the implant10, a seal 34 (e.g., a rubber stopper or similar device) is placedinside or on top of the internal chamber 20 so that it seals against theinner surface 14 of the body 12, thereby creating an airtight seal. Inturn, the tube 32 is advanced into a channel or bore that passes throughthe seal 34 and exits into the internal chamber 20. When a user actuatesthe plunger 31 of the syringe 30 by pulling it upward, air within thechamber 20 and the arms or fins 18 is removed, evacuated or sucked fromthe implant 10, thereby creating and distributing a negative pressuregradient across the implant 10 and its arms or fins 18. This negativepressure gradient created across the implant system facilitates andencourages (into the implant and its porous arms), the ingrowth ofsurrounding bony and soft tissues. Moreover, in the negative pressuregradient mode, fluid, toxins, microbes and other metabolic or biologiccomponents can be drained from the implantation site, thereby reducingassociated infection risks, as well as promoting post-surgical healing.

In addition to the negative pressure gradient mode, the presentinvention is also configured to create and distribute across the implant10 a positive pressure gradient in accordance with certain embodiments.To create and distribute a positive pressure gradient across the implant10, a seal 34 (e.g., a rubber stopper or similar device) is placedinside the internal chamber 20 so that it seals against the innersurface 14 of the body 12, thereby creating an airtight seal. In turn, atube 32 is connected to a syringe 30 and then advanced into a channel orbore that passes through the seal 34 and then exits into the internalchamber 20. When a user actuates the plunger 31 of the syringe 30 bypushing it downward, liquid can be introduced into the chamber 20 andthe arms or fins 18 and ultimately pushed out of the implant 10, therebycreating and distributing a positive pressure gradient across theimplant 10 and its arms or fins 18. In a positive pressure gradientmode, the arms or fins 18 are configured to act as a manifold fordistributing a pharmacological agent throughout the implantation site.En other words, the syringe 30 is capable of delivering apharmacological agent through the airtight seal 34 and into the internalchamber 20, where the agent can in turn leach out into the arms or fins18 to displace bodily fluids and toxins occupying the interstitialspaces in the arms and fins 18, thereby reducing or eliminating anenvironment in which microbes and metabolic products can develop andinfect the implantation site. It should be understood and appreciatedherein that various types of pharmacological agents can be used inaccordance with the teachings of the present invention, including, butnot limited to, one or more of medicines, antibiotics, growth factorsand blood platelets.

As mentioned above, the biological pressure gradients that can becreated in accordance with the present invention not only enhancepost-surgical recovery and healing (e.g., by assisting with woundclosure and the application of suction forces for draining bodily fluidsand exudates), but they also directly counter the onset of infectiousconditions. Moreover, the pressure gradients may also be used toirrigate wound sites by infusing them with the various pharmacologicalagents discussed above.

As is also mentioned above, the disclosed pressurizable implants of thepresent invention are intended to be useful for various orthopedicprocedures, including, but not limited to, shoulders, knees, hips, andvarious other joints. FIGS. 5-7, for instance, illustrate the use of thepressurizable implant device 10 as part of a stemless shoulder system.In accordance with this illustration, a humeral head component 50 isfitted inside a top portion of the internal chamber 20 of the body 12.In essence, the humeral head component 50 is shaped to fit into the samespace that the airtight seal 34 would temporarily reside when a user ispressurizing the implant as described above. After the appropriatepressure gradient has been created and distributed across the implant,the humeral head component 50 is fitted into the implant (see FIG. 6)and then surgically implanted into the humerus 40 as a pressurizedshoulder prosthesis (see FIG. 7).

It should be understood and appreciated herein that while the presentdisclosure includes various embodiments showing the biological pressuregradients being created with a standard syringe device, other devicescapable of achieving a negative and/or positive pressure gradient mayalso be used including, but not limited to, standard operating roomsuction devices, air pumping apparatuses, vacuum devices, etc.Accordingly, the present invention is not intended to be limited herein.

It should also be understood and appreciated herein that in accordancewith certain aspects of the present invention, it may be desirable toutilize a biological surface coating (e.g., a titanium porous plasmaspray (PPS®) surface coating or a biomimetic coating (e.g., BoneMaster®coating), both of which are commercially available from Biomet), withthe porous or nonporous surfaces to create a barrier to particulatedebris (metallic, polyethylene or PMMA) and/or to further promote andincrease the fixation of the bony ingrowth.

While an exemplary embodiment incorporating the principles of thepresent invention has been disclosed hereinabove, the present inventionis not limited to the disclosed embodiments. Instead, this applicationis intended to cover any variations, uses, or adaptations of theinvention using its general principles. Further, this application isintended to cover such departures from the present disclosure as comewithin known or customary practice in the art to which this inventionpertains and which fall within the limits of the appended claims.

1-15. (canceled)
 16. A method of distributing a pressure gradient acrossan implant, the method comprising: providing an implant having a body,an internal chamber and at least one porous arm extending from andinterconnected to the internal chamber via a channel or duct; placing anairtight seal in the internal chamber; connecting a device to theairtight seal; and actuating the device to create a pressuredifferential across at least a portion of the implant.
 17. The method ofclaim 16, wherein connecting the device to the airtight seal comprises:connecting a syringe to the airtight seal.
 18. The method of claim 17,wherein creating the pressure differential comprises: distributing anegative pressure gradient across the at least one porous arm byremoving air through the airtight seal upon actuating the syringe. 19.The method of claim 17, wherein creating the pressure differentialcomprises: distributing a positive pressure gradient across the at leastone porous arm by delivering a pharmacological agent through theairtight seal upon actuating the syringe.
 20. The method of claim 16,further comprising: removing the airtight seal from the implant.
 21. Themethod of claim 19, wherein the pharmacological agent includes at leastone of medicines, antibiotics, growth factors and blood platelets. 22.The method of claim 16, wherein the airtight seal is a rubber stopper.23. The method of claim 16, wherein the body is shaped as a cylinder anddefines a longitudinal axis.
 24. The method of claim 23, wherein theimplant includes a plurality of porous arms interconnected to the bodyat a single location along the longitudinal axis.
 25. A method fordistributing a negative pressure gradient across an implant, the methodcomprising: providing an implant having a body, an internal chamber andat least one porous arm extending from and interconnected to theinternal chamber via a channel or duct; placing a rubber stopper atleast partially within the internal chamber; connecting a syringe to therubber stopper; and pulling on a plunger of the syringe to remove airthrough the rubber stopper, thereby distributing a negative pressuregradient across the at least one porous arm.
 26. The method of claim 25,further comprising: removing the rubber stopper from the implant. 27.The method of claim 25, wherein the body is shaped as a cylinder anddefines a longitudinal axis.
 28. The method of claim 27, wherein theimplant includes a plurality of porous arms interconnected to the bodyat a single location along the longitudinal axis.
 29. A method fordistributing a positive pressure gradient across an implant, the methodcomprising: providing an implant having a body, an internal chamber andat least one porous arm extending from and interconnected to theinternal chamber via a channel or duct; placing a rubber stopper atleast partially within the internal chamber; connecting a syringe to therubber stopper; pushing on a plunger of the syringe to deliver apharmacological agent through the rubber stopper, thereby distributing apositive pressure gradient across the at least one porous arm.
 30. Themethod of claim 29, further comprising: removing the rubber stopper fromthe implant.
 31. The method of claim 29, wherein the pharmacologicalagent includes at least one of medicines, antibiotics, growth factorsand blood platelets.
 32. The method of claim 29, wherein the body isshaped as a cylinder and defines a longitudinal axis.
 33. The method ofclaim 32, wherein the implant includes a plurality of porous armsinterconnected to the body at a single location along the longitudinalaxis.